On Aquatic Carnivorous Coleoptera or Dytiscide, 555 
deflexed, acute apex ; the apical ventral segment bears a rather short carina, but 
no lateral rugosities. 
This species though excessively similar to Dytiscus guttiger, seems to differ by 
the more sinuate anterior claws of the male, and the less thickened and less obtuse 
outer claw of the hind foot, as well as by other slight distinctions. 
North America. 847, 
790. Ilybius zenescens, Th. Op. Ent. II, p. 125.—Ovalis, haud elongatus, subde- 
pressus, fere opacus, subtus nigricans, prosterno elytrorumque epipleuris rufo- 
obscuris, supra zeneus, capite anterius prothoracisque lateribus rufescentibus, 
antennis pedibusque rufis ; elytris densius subtiliter reticulatis, punctis subseriatis 
minus conspicuis, guttulisque duabus testaceis indistinctis ; coxis posterioribus 
obsoletissime strigosulis et punctatis, margine anteriore extus fere abrupte deflexo ; 
impressione metasternali minus elongato. Long. 83, lat. 43 m.m. 
The male has the basal joints of the front and middle tarsi slightly incrassate, 
and furnished beneath with moderately long hairs bearinz minute palettes; the 
anterior claws are simple ; on the hind feet the outer claw is but little shorter than 
the inner, and has a subacute apex; the apical ventral segment has a very short 
carina at the apex, and no distinct rugosities ; in the female the last ventral segment 
bears a rather broad but not deep emargination, in the middle of which there is 
almost no projection. 
The species is excessively closely allied to Dytiscus guttiger (No. 788), but besides 
the slight differences in colour and sculpture, the sexual characters are also a little 
dissimilar. 
Northern Europe, Siberia ; (Sweden ; Finland, to 66° 30’, Sahlberg ; Scotland, Belgium, France, Germany, 
Lithuania). 848. 
791. Dytiscus angustior, Gyll., Ilybius angustior, M.C.—Ovalis, subdepressus, 
subopacus, niger, supra eneus, antennis pedibusque rufis, illis articulis 7-10 
seepius extrorsum infuscatis, elytris densius subtiliter reticulatis, punctis subseriatis 
minus conspicuis, guttulis duabus testaceis indistinctis ; coxis posterioribus sub- 
tiliter strigosulis, margine anteriore externe leviter deflexo; prosterni processu 
apice minus clongato. Long. 93, lat. 5 m.m. 
The male has the basal joints of the front and middle tarsi a little incrassate 
and furnished beneath with moderately long hairs which bear minute palettes ; 
the claws of the front feet are simple: on the hind feet, the outer claw is shorter 
than the inner, and is obtuse at the extremity; the apical ventral segment 
has a rather sharply elevated carina, and is rugose with elongate coarse striz. 
In the female the last ventral segment has an emargination at the apex, in the 
middle of which there is a coarse fold or plica. 
TRANS, ROY. DUS. SOC., N.S, VOL. If. ‘ 4C 
